C8051T603-GS Silicon Laboratories Inc, C8051T603-GS Datasheet - Page 138

• Manufacturer Part Number: C8051T603-GS
• Description: IC 8051 MCU 4K-EEPROM 14-SOIC
• Manufacturer: Silicon Laboratories Inc
• Series: C8051T60xr

Specifications of C8051T603-GS

• Program Memory Type: OTP
• Program Memory Size: 4KB (4K x 8)
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051T6x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C/SMBus/UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 8
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051T600DK
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1404 - KIT DEV FOR C8051T60X MCU'S
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1657-5

C8051T600/1/2/3/4/5/6
24.1. Enhanced Baud Rate Generation
The UART0 baud rate is generated by Timer 1 in 8-bit auto-reload mode. The TX clock is generated by
TL1; the RX clock is generated by a copy of TL1 (shown as RX Timer in Figure 24.2), which is not user-
accessible. Both TX and RX Timer overflows are divided by two to generate the TX and RX baud rates.
The RX Timer runs when Timer 1 is enabled, and uses the same reload value (TH1). However, an
RX Timer reload is forced when a START condition is detected on the RX pin. This allows a receive to
begin any time a START is detected, independent of the TX Timer state.
Timer 1 should be configured for Mode 2, 8-bit auto-reload (see Section “25.1.3. Mode 2: 8-bit Coun-
ter/Timer with Auto-Reload” on page 149). The Timer 1 reload value should be set so that overflows will
occur at two times the desired UART baud rate frequency. Note that Timer 1 may be clocked by one of six
sources: SYSCLK, SYSCLK/4, SYSCLK/12, SYSCLK/48, the external oscillator clock/8, or an external
input T1. For any given Timer 1 clock source, the UART0 baud rate is determined by Equation 24.1-A and
Equation 24.1-B.
Where T1
value). Timer 1 clock frequency is selected as described in Section “25. Timers” on page 145. A quick ref-
erence for typical baud rates and system clock frequencies is given in Table 24.1 through Table 24.2. The
internal oscillator may still generate the system clock when the external oscillator is driving Timer 1.
138
CLK
is the frequency of the clock supplied to Timer 1 and T1H is the high byte of Timer 1 (reload
Detected
Start
A)
B)
Figure 24.2. UART0 Baud Rate Logic
UartBaudRate
T1_Overflow_Rate
Equation 24.1. UART0 Baud Rate
RX Timer
Timer 1
TH1
TL1
=
Overflow
Overflow
Rev. 1.2
1
-- -
2

=
T1_Overflow_Rate
------------------------- -
256 TH1
T1
–
CLK
2
2
UART
RX Clock
TX Clock